Liquid crystal displays (LCDs) are used in many electronic products today. For example, with respect to mobile applications, a mobile device display should be viewable under strong ambient light as well as in the dark. In the dark, a backlight is provided so that the LCD operates in a transmittive mode, i.e., the generated light is transmitted through the LCD. When there is sufficient ambient light, the LCD should be able to operate in a reflective mode, meaning that the display is made visible by ambient light reflecting from the LCD. In order for both the reflective mode and the transmittive mode to be possible, the reflectance-voltage curve (RVC) and the transmittance-voltage curve (TVC) should overlap.
Numerous types of transflective displays are known. For example, Huang et al. (U.S. Pat. No. 6,801,281) teaches a method of fabricating a reflector so that the reflective light path is the same distance as the transmittive light path. Another reference, Kim (U.S. Pat. No. 6,912,027), teaches a transflective display having two different cell gaps. Similarly, Kubota et al. (U.S. Pat. No. 6,836,306) teaches a transflective LCD having two cell gaps and two twist angles wherein the cell gap and twist angle ratios are the same. The Chang et al. reference (U.S. Pat. No. 7,239,365) teaches a transflective display wherein the electrodes are patterned into strips so that a lateral field is generated to provide switching of the reflective and transmittive displays. In U.S. Pat. No. 5,926,245, Kwok et al. teaches a design having a single polarizer display. These reflective LC modes are useful in the design of transflective displays.
However, despite the numerous attempts to develop a display having optimal transmittive and reflective characteristics that can be produced in an economical and efficient manner, such a system has not been fully realized.